Tree stand



FIG. 1 is a top perspective view of a tree stand showing my new design;

FIG. 2 is a bottom perspective view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof; and,

FIG. 5 is a front elevational view thereof, with the rear elevational view, left side elevational view and right side elevational view being identical.

The broken lines shown in the drawings represent portions of the tree stand that form no part of the claimed design. 

CLAIM The ornamental design for a tree stand, as shown and described. 